Determining associations between users of mobile devices can be useful in a variety of ways to enhance functionality of mobile devices (e.g., smartphones, watches, etc.). These associations can indicate whether users of mobile devices are friends, communicate often, or are otherwise related. Certain techniques for determination association include manual selection of associations. For example, two users can be “friends” on a social media platform by manually indicating that they are friends via a user interface of the social media platform. This association can allow the users to enhance their interaction with each other through the social media platform. However, manually selecting associations between users can limit opportunities to provide enhanced functionality to associated users. Consequently, ways of improving detection of user associations through use of mobile devices are desirable.